Ceramic flat sheet membrane support, method of making and use in ceramic flat sheet membranes

Abstract

The application belongs to the technical field of ceramic product preparation, and particularly relates to a ceramic flat plate membrane support body, a preparation method thereof and application of the ceramic flat plate membrane support body in a ceramic flat plate membrane. The preparation method of the ceramic flat plate membrane support body comprises the following steps: uniformly dry mixing corundum aggregate, mullite fiber, zirconia, kaolin, a binder and a pore-forming agent to obtain a mixture; preparing a colloidal mud slurry, adding the colloidal mud slurry into the mixture while stirring, stirring into a mud ball, and kneading into a ball; spiral extruding and cutting the mud ball, then performing vacuum mud conditioning, cutting and aging after filtration, vacuum extruding, drying, and obtaining a ceramic flat plate membrane support body green body; and high-temperature sintering the ceramic flat plate membrane support body green body to obtain the ceramic flat plate membrane support body. The preparation method of the ceramic flat plate membrane support body provided by the application improves the bending strength and fracture toughness of the ceramic flat plate membrane after the prepared support body is used in the ceramic flat plate membrane, and further prolongs the service life of the ceramic flat plate membrane.

Description

Technical Field

[0001] This invention belongs to the field of ceramic product preparation technology, specifically relating to ceramic flat sheet membrane supports, their preparation methods, and their application in ceramic flat sheet membranes. Background Technology

[0002] Ceramic flat sheet membranes possess advantages such as good thermal stability, high chemical stability, and high permeation flux, making them particularly effective in wastewater filtration and thus widely used in the environmental industry. Ceramic flat sheet membranes consist of a support structure and membrane layers.

[0003] Currently, common ceramic flat sheet membrane products on the market, due to functional requirements, have a high porosity and low flexural strength in their support materials. Furthermore, because the support structure of ceramic flat sheet membranes is typically plate-like, with thin walls and multi-channel hollow structures, these products are highly susceptible to structural cracking, breakage, and even bursting during wastewater filtration due to fouling, backwashing, or prolonged aeration and vibration. This severely impacts the lifespan of the ceramic flat sheet membrane products.

[0004] CN113385052A discloses an alumina-based ceramic flat sheet film. The support body is formed by mixing near-spherical alumina powder with an average particle size of 3-50 μm with a pore-forming agent, binder, washed kaolin, calcined talc, and sintering aids (two or more of silica sol, nano-titanium dioxide, nano-zirconia, nano-zinc oxide, washed kaolin, and calcined talc) in a mixer to form a powder. A lubricant and plasticizer solution are stirred and mixed evenly, and then added to the mixed powder in a ceramic clay kneader for kneading and mixing. After clay aging, vacuum kneading, extrusion molding, and wet blank drying, a green support body for coating is obtained. However, in this method, the sintering aids are difficult to disperse evenly. Uneven sintering of the sintering aids will cause uneven sintering of the support body, easily leading to low strength in areas with less aid during use, resulting in backwashing cracking or even explosion.

[0005] CN111420562A discloses a method for preparing a hollow flat ceramic membrane. Spherical alumina, magnesium oxide, and kaolin are used as ceramic aggregates. These aggregates are then mixed with a pore-forming agent, a green body binder, polyethylene glycol, and water. The mixture is poured into a vacuum ply mill for plying, and finally aged in a sealed container to obtain a supporting body material. After extrusion, drying, and sintering, a microporous membrane slurry (obtained by ball milling spherical alumina, kaolin, potassium feldspar, polyethylene glycol, silica sol, and water) is sprayed onto both sides. Finally, the membrane is fired to obtain a hollow flat ceramic membrane with high mechanical strength and improved service life. However, the flat ceramic membrane prepared by this method has poor fracture toughness, poor dispersion of the sintering aid, poor uniformity during sintering, and is prone to cracking. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a method for preparing a ceramic flat sheet membrane support. When the prepared support is used in a ceramic flat sheet membrane, it improves the bending strength and fracture toughness of the ceramic flat sheet membrane, thereby extending the service life of the ceramic flat sheet membrane.

[0007] The method for preparing the ceramic flat film support of the present invention includes the following steps:

[0008] (1) Dry mix corundum aggregate, mullite fiber, zirconium oxide, kaolin, binder and pore-forming agent evenly to obtain a mixture;

[0009] (2) Preparation of colloidal slurry: Add inorganic oxides to water, then add cellulose, dispersant and PVA colloid, grind at 1500-2000 r / min for 2-4 h to obtain colloidal slurry;

[0010] (3) Add colloidal mud to the mixture while stirring, stir to form mud balls, knead for 30-50 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0011] (4) The clay lump is spirally extruded and cut off, then vacuum kneaded, filtered, cut off and aged, vacuum extruded and shaped, and dried to obtain a ceramic flat film support green body.

[0012] (5) The ceramic flat sheet film support green body is fired at high temperature to obtain the ceramic flat sheet film support.

[0013] The corundum aggregate in step (1) has a particle size of 5-10 μm; the mullite fiber has an aspect ratio of 100-150; the zirconium oxide is tetragonal zirconium oxide micro powder with a particle size of 20-100 nm; the binder is powdered cellulose with a viscosity of 80000 mPa·s-200000 mPa·s and a particle size range of 120-300 mesh; and the kaolin is 8000 mesh kaolin.

[0014] The mixture in step (1) includes, by weight, 200 parts of corundum aggregate; 2-5 parts of mullite fiber; 3-6 parts of zirconium oxide; 8-12 parts of kaolin; 4-6 parts of binder; and 7-12 parts of pore-forming agent.

[0015] The pore-forming agent is one of the following: 4000-8000 mesh carbon black powder, 1000-2000 mesh starch, or 1000-2000 mesh aluminum stearate.

[0016] The colloidal slurry of step (2) comprises, by weight, 150 parts water; 3.5-7.5 parts inorganic oxides; 1-2 parts carboxymethyl cellulose; 0.5-1.5 parts dispersant; and 20-30 parts PVA colloid.

[0017] The dispersant is one of sodium tripolyphosphate, sodium lignosulfonate, or CNF.

[0018] Inorganic oxides are made by mixing the following raw materials in parts by weight: 0.5-1.5 parts titanium oxide; 1-2 parts yttrium oxide; and 2-4 parts calcium oxide.

[0019] The preparation method of PVA colloid is as follows: 100 parts by weight of water are heated to 70-100℃, then 7-9 parts of fine PVA powder are added, and the mixture is kept at this temperature for 1.9-2.2 hours until it becomes uniform and transparent, thus obtaining PVA colloid. The particle size of the fine PVA powder is 120-300 mesh.

[0020] In step (3), the mixture and colloidal slurry are added according to the following weight proportions: 600 parts of mixture and 130-150 parts of colloidal slurry.

[0021] The aging temperature in step (4) is 15-30℃, the humidity is 50-85%, the time is 2-4 days, and the drying temperature is 120-180℃.

[0022] The high-temperature firing temperature in step (5) is 1400-1550℃, and the time is 4-8h.

[0023] A ceramic flat sheet membrane support is prepared by the method described above.

[0024] One application of the ceramic flat sheet membrane support involves spraying a film layer onto the ceramic flat sheet membrane support, drying it, and firing it at 1250-1350℃ to obtain a ceramic flat sheet membrane.

[0025] Specifically, the method for preparing the ceramic flat sheet membrane includes the following steps:

[0026] (1) Mix 200 parts of 5-10μm corundum aggregate, 2-5 parts of mullite fiber with an aspect ratio of 100-150, 3-6 parts of tetragonal zirconium oxide with a diameter of 20-100nm, 8-12 parts of 8000 mesh kaolin, 4-6 parts of cellulose powder with a particle size of 120-300 mesh and a viscosity of 80000mPa·s-200000mPa·s, and 7-12 parts of pore-forming agent evenly in a dry mixer to obtain a mixture.

[0027] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 0.5-1.5 parts of titanium oxide, 1-2 parts of yttrium oxide, 2-4 parts of calcium oxide, 1-2 parts of carboxymethyl cellulose, 0.5-1.5 parts of dispersant, and 20-30 parts of PVA colloid to a high-speed stirred mill. Grind at 1500-2000 r / min for 2-4 h to mix into a uniform slurry with excellent fluidity, and obtain colloidal slurry;

[0028] The method for preparing the PVA colloid is as follows: according to the weight, add 100 parts of pure water to a water bath colloid pot, heat to 70-100℃, then add 7-9 parts of fine PVA powder, keep warm for 1.9-2.2 hours, and cook until uniform and transparent to obtain PVA colloid.

[0029] (3) Release 600 parts of the mixture into a wet kneader, add 130-150 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 30-50 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0030] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 10-15cm and a weight of 3-5kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 6-8 times with a maximum filtration accuracy of 100 mesh. After cutting, age it for 2-4 days at a temperature of 15-30℃ and a humidity of 50-85%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 120-180℃ to obtain a ceramic flat film support green body.

[0031] (5) The ceramic flat film support green body is stacked in a pile of 5-10 pieces and placed in a high-temperature kiln. It is fired at 1400-1550℃ for 4-8 hours and then cooled to obtain the ceramic flat film support body.

[0032] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1250-1350℃ to obtain a ceramic flat sheet membrane.

[0033] The method for preparing the ceramic flat sheet membrane of the present invention firstly involves mixing inorganic oxides titanium dioxide, yttrium oxide, and calcium oxide as composite sintering aids with carboxymethyl cellulose, dispersant, and PVA colloid in a colloidal slurry and grinding and mixing them. Then, it is mixed with corundum aggregate, mullite fiber, zirconium oxide, and other materials, kneaded into a mud ball, and then subjected to kneading, aging, drying, and firing treatments. This method solves the problem of uneven distribution of sintering aids in the support body and further addresses the issue that ceramic flat sheet membranes are prone to low strength in areas with insufficient aids during use, leading to backwashing cracking or even explosion.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] (1) The ceramic flat sheet membrane prepared by the method of the present invention has improved the bending strength and fracture toughness.

[0036] (2) The ceramic flat sheet membrane prepared by the method of the present invention reduces the risk of cracking and bursting during the backwashing process after clogging.

[0037] (3) The ceramic flat sheet membrane prepared by the method of the present invention has a long service life. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments.

[0039] The raw materials and additives used in the following examples and comparative examples are all commercially available products. The purchased corundum aggregate has a particle size of 5-10 μm; the mullite fiber has an aspect ratio of 100-150; the zirconium oxide is tetragonal zirconium oxide with a diameter of 20-100 nm; the kaolin is 8000 mesh; the cellulose powder has a viscosity of 80000 mPa·s-200000 mPa·s and a particle size of 120-300 mesh; and the PVA fine powder has a particle size of 120-300 mesh. All parts or weights mentioned below are by mass.

[0040] The high-speed mixing mill, kneader, and dry mixer used are all applications of existing technologies, so they will not be discussed further.

[0041] Example 1

[0042] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0043] (1) Mix 200 parts of corundum aggregate, 4 parts of mullite fiber, 5 parts of zirconium oxide, 10 parts of kaolin, 5 parts of cellulose powder, and 9 parts of carbon black powder of 4000-8000 mesh in a dry mixer to obtain a mixture.

[0044] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 1 part of titanium oxide, 1 part of yttrium oxide, 3 parts of calcium oxide, 1 part of carboxymethyl cellulose, 1 part of sodium tripolyphosphate, and 25 parts of PVA colloid to a high-speed stirring mill, grind at 2000 r / min for 3 h, mix into a uniform slurry with excellent fluidity, and obtain colloidal slurry.

[0045] The method for preparing the PVA colloid is as follows: according to the weight parts, add 100 parts of pure water to a water bath colloid pot, heat to 90°C, then add 8 parts of fine PVA powder, keep warm for 2.0 hours, and cook until uniform and transparent to obtain PVA colloid.

[0046] (3) Release 600 parts of the mixture into a wet kneader, add 140 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 40 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0047] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 14cm and a weight of 4kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 7 times with a filtration accuracy of 100 mesh. After cutting, age it for 3 days at a temperature of 20℃ and a humidity of 70%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 160℃ to obtain a ceramic flat film support green body.

[0048] (5) The ceramic flat film support green body is stacked in groups of 8 and placed in a high-temperature kiln. It is fired at 1500℃ for 6 hours and then cooled to obtain the ceramic flat film support body.

[0049] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1300℃ to obtain a ceramic flat sheet membrane.

[0050] Example 2

[0051] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0052] (1) Mix 200 parts of corundum aggregate, 5 parts of mullite fiber, 3 parts of zirconium oxide, 8 parts of kaolin, 4 parts of cellulose powder, and 12 parts of 1000-2000 mesh aluminum stearate evenly in a dry mixer to obtain a mixture.

[0053] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 1.5 parts of titanium oxide, 1 part of yttrium oxide, 4 parts of calcium oxide, 1 part of carboxymethyl cellulose, 0.5 parts of CNF, and 30 parts of PVA colloid to a high-speed stirring mill, grind at 1800 r / min for 2 h, mix into a uniform slurry with excellent fluidity, and obtain colloidal slurry.

[0054] The method for preparing the PVA colloid is as follows: according to the weight parts, add 100 parts of pure water to a water bath colloid pot, heat to 100℃, then add 9 parts of fine PVA powder, keep warm for 1.9h, and cook until uniform and transparent to obtain PVA colloid.

[0055] (3) Release 600 parts of the mixture into a wet kneader, add 130 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 30 minutes, and knead into mud balls with an average diameter of 50cm.

[0056] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 15cm and a weight of 5kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 8 times with a filtration accuracy of 100 mesh. After cutting, age it for 4 days at a temperature of 30℃ and a humidity of 50%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 180℃ to obtain a ceramic flat film support green body.

[0057] (5) The ceramic flat film support green body is stacked in a row of 5 pieces and placed in a high-temperature kiln. It is fired at 1400℃ for 8 hours and then cooled to obtain the ceramic flat film support body.

[0058] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1250℃ to obtain a ceramic flat sheet membrane.

[0059] Example 3

[0060] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0061] (1) Mix 200 parts of corundum aggregate, 2 parts of mullite fiber, 6 parts of zirconium oxide, 12 parts of kaolin, 6 parts of cellulose powder, and 7 parts of starch with a mesh size of 1000-2000 in a dry mixer to obtain a mixture.

[0062] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 0.5 parts of titanium oxide, 2 parts of yttrium oxide, 2 parts of calcium oxide, 2 parts of carboxymethyl cellulose, 1.5 parts of sodium lignosulfonate, and 20 parts of PVA colloid to a high-speed stirred mill, grind at 1500 r / min for 4 h, mix into a uniform slurry with excellent fluidity, and obtain colloidal slurry;

[0063] The method for preparing the PVA colloid is as follows: according to the weight parts, add 100 parts of pure water to a water bath colloid pot, heat to 70°C, then add 7 parts of fine PVA powder, keep warm for 2.2 hours, and cook until uniform and transparent to obtain PVA colloid.

[0064] (3) Release 600 parts of the mixture into a wet kneader, add 150 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 30 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0065] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 10cm and a weight of 3kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 6 times with a filtration accuracy of 100 mesh. After cutting, age it for 2 days at a temperature of 15℃ and a humidity of 85%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 120℃ to obtain a ceramic flat film support green body.

[0066] (5) The ceramic flat film support green body is stacked in groups of 10 and placed in a high-temperature kiln. It is fired at 1550℃ for 4 hours and then cooled to obtain the ceramic flat film support body.

[0067] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1350℃ to obtain a ceramic flat sheet membrane.

[0068] Example 4

[0069] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0070] (1) Mix 200 parts of corundum aggregate, 3 parts of mullite fiber, 5 parts of zirconium oxide, 9 parts of kaolin, 4 parts of cellulose powder, and 7 parts of 1000-2000 mesh starch evenly in a dry mixer to obtain a mixture.

[0071] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 1.5 parts of titanium oxide, 2 parts of yttrium oxide, 4 parts of calcium oxide, 2 parts of carboxymethyl cellulose, 0.5 parts of sodium tripolyphosphate, and 30 parts of PVA colloid to a high-speed stirred mill, grind at 2000 r / min for 3 h, mix into a uniform slurry with excellent fluidity, and obtain colloidal slurry;

[0072] The method for preparing the PVA colloid is as follows: according to the weight parts, add 100 parts of pure water to a water bath colloid pot, heat to 90°C, then add 9 parts of fine PVA powder, keep warm for 2.0 hours, and cook until uniform and transparent to obtain PVA colloid.

[0073] (3) Release 600 parts of the mixture into a wet kneader, add 145 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 50 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0074] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 12cm and a weight of 4kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 8 times with a filtration accuracy of 100 mesh. After cutting, age it for 4 days at a temperature of 25℃ and a humidity of 65%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 160℃ to obtain a ceramic flat film support green body.

[0075] (5) The ceramic flat film support green body is stacked in a row of 10 pieces and placed in a high-temperature kiln. It is fired at 1480℃ for 6 hours and then cooled to obtain the ceramic flat film support body.

[0076] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1300℃ to obtain a ceramic flat sheet membrane.

[0077] Example 5

[0078] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0079] (1) Mix 200 parts of corundum aggregate, 5 parts of mullite fiber, 6 parts of zirconium oxide, 12 parts of kaolin, 4 parts of cellulose powder, and 12 parts of starch of 1000-2000 mesh in a dry mixer to obtain a mixture.

[0080] (2) Preparation of colloidal slurry: Add 150 parts of pure water, 1 part of titanium oxide, 1.5 parts of yttrium oxide, 3.5 parts of calcium oxide, 1.5 parts of carboxymethyl cellulose, 1 part of sodium tripolyphosphate, and 25 parts of PVA colloid to a high-speed stirred mill, grind at 1500 r / min for 3 h, and mix into a uniform slurry with excellent fluidity to obtain colloidal slurry;

[0081] The method for preparing the PVA colloid is as follows: according to the weight parts, add 100 parts of pure water to a water bath colloid pot, heat to 85°C, then add 9 parts of fine PVA powder, keep warm for 2 hours, and cook until uniform and transparent to obtain PVA colloid.

[0082] (3) Release 600 parts of the mixture into a wet kneader, add 145 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 50 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0083] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 12cm and a weight of 3.5kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 8 times with a filtration accuracy of 100 mesh. After cutting, age it for 3 days at a temperature of 30℃ and a humidity of 75%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 170℃ to obtain a ceramic flat film support green body.

[0084] (5) The ceramic flat film support green body is stacked in groups of 8 and placed in a high-temperature kiln. It is fired at 1480℃ for 8 hours and then cooled to obtain the ceramic flat film support body.

[0085] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1300℃ to obtain a ceramic flat sheet membrane.

[0086] Comparative Example 1

[0087] This comparative example is the same as Example 1, except that the "4 parts of mullite fiber" in step (1) is removed, and the other preparations are the same as in Example 1.

[0088] Comparative Example 2

[0089] This comparative example is the same as Example 1, except that "5 parts of zirconium oxide" in step (1) is removed, and the other preparations are the same as in Example 1.

[0090] Comparative Example 3

[0091] This comparative example is the same as Example 1, except that in step (2), "add 1 part of titanium oxide, 1 part of yttrium oxide, and 3 parts of calcium oxide" is replaced with "add 4 parts of titanium oxide and 3 parts of calcium oxide". The other preparations are the same as in Example 1.

[0092] Comparative Example 4

[0093] This comparative example is the same as Example 1, except that in step (2), "adding 1 part of titanium oxide, 1 part of yttrium oxide, and 3 parts of calcium oxide" is replaced with "adding 5 parts of magnesium oxide". The other preparations are the same as in Example 1.

[0094] Comparative Example 5

[0095] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0096] (1) Mix 200 parts of corundum aggregate, 4 parts of mullite fiber, 5 parts of zirconium oxide, 10 parts of kaolin, 5 parts of cellulose powder, and 9 parts of carbon black powder of 4000-8000 mesh in a dry mixer to obtain a mixture.

[0097] (2) Preparation of colloidal slurry: Add 250 parts of pure water, 1 part of titanium oxide, 1 part of yttrium oxide, 3 parts of calcium oxide, 1 part of carboxymethyl cellulose, 1 part of sodium tripolyphosphate, and 25 parts of PVA fine powder to a high-speed stirred mill. Then add PVA fine powder and grind at 2000 r / min for 3 h to mix into a uniform slurry with excellent fluidity, thus obtaining colloidal slurry.

[0098] (3) Release 600 parts of the mixture into a wet kneader, add 140 parts of colloidal mud while stirring, gradually stir into mud balls, knead for 40 minutes, and knead into mud balls with an average diameter of 20-50cm.

[0099] (4) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 14cm and a weight of 4kg at the outlet. Automatically transfer it to the vacuum mud filter machine for vacuum mud filtration 7 times with a filtration accuracy of 100 mesh. After cutting, age it for 3 days at a temperature of 20℃ and a humidity of 70%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 160℃ to obtain a ceramic flat film support green body.

[0100] (5) The ceramic flat film support green body is stacked in groups of 8 and placed in a high-temperature kiln. It is fired at 1500℃ for 6 hours and then cooled to obtain the ceramic flat film support body.

[0101] (6) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1300℃ to obtain a ceramic flat sheet membrane.

[0102] Comparative Example 6

[0103] The method for preparing the ceramic flat sheet membrane includes the following steps:

[0104] (1) Mix 200 parts of corundum aggregate, 4 parts of mullite fiber, 5 parts of zirconium oxide, 10 parts of kaolin, 5 parts of cellulose powder, and 9 parts of carbon black powder of 4000-8000 mesh in a dry mixer until uniform. Then add 1 part of titanium oxide, 1 part of yttrium oxide, 3 parts of calcium oxide, 1 part of carboxymethyl cellulose, 1 part of sodium tripolyphosphate, and 25 parts of PVA fine powder. Release the mixture into a wet mixing kneader and add 150 parts of pure water while stirring. Grind at 2000 r / min for 3 hours, gradually stirring into a mud ball. Knead for 40 minutes to form a mud ball with an average diameter of 20-50 cm.

[0105] (2) Turn on the screw extrusion of the kneader and gradually extrude the mud from the bottom. Cut it into mud blocks with a width of 14cm and a weight of 4kg at the outlet. Automatically transfer it to the vacuum filter mud machine for vacuum kneading and filtration 7 times with a filtration accuracy of 100 mesh. After cutting, age it for 3 days at a temperature of 20℃ and a humidity of 70%. Use a vacuum extruder to vacuum extrude and shape it. Dry it at 160℃ to obtain a ceramic flat film support green body.

[0106] (3) The ceramic flat film support green body is stacked in groups of 8 and placed in a high-temperature kiln. It is fired at 1500℃ for 6 hours and then cooled to obtain the ceramic flat film support body.

[0107] (4) Spray a film layer onto the ceramic flat sheet membrane support, dry it, and fire it at 1300℃ to obtain a ceramic flat sheet membrane.

[0108] The ceramic flat film prepared in the above examples and comparative examples was tested for flexural strength and fracture toughness, and the test results are shown in Table 1.

[0109] Table 1 Test Results

[0110]

[0111] Of course, the above description is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the embodiments of the present invention. The present invention is also not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of the present invention should fall within the patent coverage of the present invention.

Claims

1. A method for preparing a ceramic flat sheet membrane support, characterized in that: Includes the following steps: (1) Dry mix the corundum aggregate, mullite fiber, zirconium oxide, kaolin, binder and pore-forming agent evenly to obtain a mixture; The pore-forming agent is one of the following: 4000-8000 mesh carbon black powder, 1000-2000 mesh starch, or 1000-2000 mesh aluminum stearate. (2) Preparation of colloidal slurry: Add inorganic oxides to water, then add carboxymethyl cellulose, dispersant and PVA colloid, grind at 1500-2000 r / min for 2-4 h to obtain colloidal slurry; Inorganic oxides are made by mixing the following raw materials in parts by weight: 0.5-1.5 parts titanium oxide; 1-2 parts yttrium oxide; 2-4 parts calcium oxide; The preparation method of PVA colloid is as follows: according to the weight parts, 100 parts of water are heated to 70-100℃, and then 7-9 parts of PVA fine powder are added. The mixture is kept warm for 1.9-2.2 hours and boiled until it is uniform and transparent to obtain PVA colloid. The dispersant is one of sodium tripolyphosphate, sodium lignosulfonate, or CNF; (3) Add colloidal mud to the mixture while stirring, stir to form mud balls, knead for 30-50 minutes, and knead into mud balls with an average diameter of 20-50cm; (4) The clay lump is spirally extruded and cut, then vacuum kneaded, filtered, cut and aged, vacuum extruded and shaped, and dried to obtain a ceramic flat film support green body. (5) The ceramic flat sheet film support green body is fired at high temperature to obtain the ceramic flat sheet film support.

2. The method for preparing the ceramic flat film support according to claim 1, characterized in that: The corundum aggregate in step (1) has a particle size of 5-10 μm; the mullite fiber has an aspect ratio of 100-150; the zirconium oxide is tetragonal zirconium oxide with a particle size of 20-100 nm; and the binder is powdered cellulose.

3. The method for preparing the ceramic flat film support according to claim 1, characterized in that: The mixture in step (1) includes, by weight, 200 parts of corundum aggregate; 2-5 parts of mullite fiber; 3-6 parts of zirconium oxide; 8-12 parts of kaolin; 4-6 parts of binder; and 7-12 parts of pore-forming agent.

4. The method for preparing the ceramic flat film support according to claim 1, characterized in that: The colloidal slurry of step (2) comprises, by weight, 150 parts water; 3.5-7.5 parts inorganic oxides; 1-2 parts carboxymethyl cellulose; 0.5-1.5 parts dispersant; and 20-30 parts PVA colloid.

5. The method for preparing the ceramic flat film support according to claim 1, characterized in that: In step (3), the mixture and colloidal slurry are added according to the following weight proportions: 600 parts of mixture and 130-150 parts of colloidal slurry.

6. The method for preparing the ceramic flat film support according to claim 1, characterized in that: The high-temperature firing temperature in step (5) is 1400-1550℃, and the time is 4-8h.

7. A ceramic flat sheet membrane support, characterized in that: It is prepared by the method of ceramic flat film support according to any one of claims 1-6.

8. An application of the ceramic flat film support according to claim 7, characterized in that: A ceramic flat sheet membrane is obtained by spraying a membrane layer onto a ceramic flat sheet membrane support, drying, and firing.

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